Features: until recently, this 27-storey, 400,000 square foot “home” was the world’s most expensive. It was built by Indian billionaire Mukesh Ambani, and requires 600 staffers to function. It’s got all the usual supermansion features, plus three helipads, a 168-car parking garage (Ambani is a collector), and an ice room that produces snow flurries. Because why not, right?